Piano construction.



PATENTED FEB. 28, 1905.

R. W, GERTZ.

PIANO CONSTRUCTION.

APPLICATION FILED JULY 11, 1904.

3 SHEETS-SHEET 1.

N0. 788,781. PATENTED FEB. 28, 1905, R. W. GERTZ.

PIANO CONSTRUCTION:

APPLICATION FILED JULY 11, 1904.

3 SHEETS-SHEET 2.

1V0. 788,781. PATENTBD FEB. 28, 1905. R. W. GEBTZ.

PIANO CONSTRUCTION APPLICATION FILED JULY 11,1904.

3 SHEETS-SHEET 3.

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UNITED STATES Patented February 28, 1905.

PATENT OEEIcE.

PIANO CONSTRUCTION.

SPECIFICATION forming part of Letters Patent No. 783,781, dated February 28, 1905.

Application filed July 11,1904. Serial No. 215,992.

1'0 all whom it may concern.-

Be it known that I, RICHARD W. GERTZ, a citizen of the United States, and a resident of Boston, county of Suffolk, State of Massachusetts, have invented an Improvement in Piano Constructions, of which the following description, in connection with the accompanying drawings, is a specification, like characters on the drawings representing like parts.

This invention relates to pianos, and has for its. object to provide a novel construction whereby the tension on the rim supporting the sounding-board may be easily adjusted and the adjustment maintained regardless of the hygrostatic changes in the atmosphere.

In Patent No. 658,985, granted to Emil A. Gertz and myself, is illustrated and described a piano in which the rim A, to which the sounding-board is secured, as usual, is maintained at the proper tension by means of tension members (5, which pass through the rim A and have suitable heads on their ends which engage the outside of the rim. The rim A in said patent is constructed of a plurality of layers of wood placed with the grain running longitudinally thereof,and therefore the strain on the tension members is across the grain rather than in the direction of the length of the grain.

In order to-keep the sounding-board under proper tension, it is frequently necessary to tighten the tension members to such an extent that the heads on the ends of the tension members are apt to crush the grain of the wood against which they lie and to be drawn into This result is especially apt to occur whenever the rim swells any, due to moisture in the atmosphere or otherwise, for it is a well-known fact that whenever wood swells or shrinks the swelling or shrinkage takes place transversely of the grain rather than longitudinally thereof, and any swelling or shrinkage of the rim of the piano therefore causes it to increase and diminish in thickness or width. Such increase or diminution in the thickness or width of the rim not only operates to increase or vary the tension on the tension members a but frequently causes the flat heads on the end thereof to become embedded in the rim. As soon as this occurs the tension on the rim is reduced, and it becomes necessary to readjust the tension members in order to bring the sounding-board up to its proper pitch. It is to obviate this dil ficulty and to provide a construction in which the head on the end of the tension member will not become embedded in the wood of the rim under any circumstances thatI have made my present invention. 1 accomplish this object by providing the ends of the tension members with tapering heads, which are received in correspondiugly-shaped recesses in the rim. The taper on the heads, while suflicient to prevent the latter from being pulled through the rim, is such that the strain on the tension members is transmitted to the wood substantially in a direction parallel to the direction of the grain of the wood. \Vith this construction the strain on the tension members will not crush the wood, as is the case where the pressure of the head comes transversely to the grain rather than longitudinally thereof, and therefore there is no danger of the heads becoming embedded in the rim and the tension on the latter relaxed due either to swelling of the rim or to. any other cause.

In the drawings, Figure 1 is a plan view of the rim, to which the sounding-board is attached, showing my invention applied there to. Fig. 2 is a section on substantially the line in m, Fig. 1. Fig. 3 shows a modification. Fig. A is a view similar to Fig. 1, showing one of the modilied forms of the invention. Fig. is a section on the line 1/ i Fig. 3. Fig. ('3 is an enlarged detail view. Figs. T and 8 show modifications of my invention. Fig. 9 is a transverse section through Fig. 8, and Fig. 10 is a detail hereinafter referred to.

Referring first to Fig. 1, which shows :1 piano similar in general construction to that illustrated in the above-mentioned patent, A designates the inner rim, to which the sounding-board is secured, as usual, and C designates the outer rim or 'iiano-casing. In Fig. 1 the outer and inner rim are shown as separated from each other, as in the above-mentioned patent, though this construction is not essential to my invention. Said outer rim, as

usual, is constructed of a plurality of strips of wood glued together and cut so that the grain vcntion shown in Fig. 1 at their outer ends 1 fast to an anchor member 3. Each of the tension members 5 is preferably provided with a suitable turnbuckle 4, so that the tension upon any portion of the rim A may be adjusted as required. Each tension member has at its outer end a tapering head 5, which is received in a tapering aperture in the rim A. make these heads substantially frusto-eonical would answer the purpose equally well. Said heads may be either integral with the tension members 5 or secured thereto in any suitable way. In the drawings 1 have illustrated the heads 5 as screw-threaded to the ends of the tension members 07 as seen in Fig. 2. The taper on the heads 5,while being sufficient to prevent them from pulling through the rim by the tension on the tension members, is such that the pressure or strain of the head on or against the rim is transmitted to the latter in a direction substantially parallel to the direction of the grain of the wood rather than across the grain. Since wood will withstand a much greater pressure without being crushed when the pressure is transmitted to it in the direction substantially parallel to its grain instead of across or transversely to the grain it follows that with my improved construction even the greatest tension to which the tension members are subjected will not cause the heads thereof to crush the wood of the rim and become embedded therein. Therefore any swelling of the rim tending to expand its w dth does not effect the tension on the tension members or cause the heads thereof to embed themselves in the rim, as would be the case if said tension members were provided with flat heads engaging the rim in such a way that the pressure of the tension was transmitted to the rim transversely of the grain, as in the above-mentioned patent. After the tension members have been once adjusted therefore it is unnecessary to readjust them every time the thickness of the rim changes by reason of any hygrostatic changes in the atmosphere.

In Fig. 3 I have illustrated a little different form of my invention, in which the inner rim A and the outer rim 0 are secured together, as is usually the case in grand pianos. The tension members a are also arranged slightly differently, they extending parallel to each other instead of radially from the center anchor, as in Fig. 1. These tension members (45 will each preferably be provided with a turnbuckle 4, so that the tension thereon may be varied, and at their ends have the tapered heads 5, which are received in tapered recesses or apertures in the rim A.

It sometimes happens that in tightening one tension member to put the rim adjacent thereto under the proper tension some other portion of the rim may be drawn inwardly too far, thus throwing the rim out of shape or changing its tension at this point. To pre vent this, I propose to employ in connection with my tension members suitable abutments or stops which engage the inside of the rim and hold itin proper shape. In the preferred embodiment of my invention these abutments j or stops are adjustable and are carried by the I prefer to tensionmembers, said abutments being in the i form of nuts screw-tlucaded to said tension m shape, although any other tapering shape F members and acting against the inside of the rim. For this purpose .I have shown a portion of the head 5 screw-threzuled, as at 7, and have mounted thereon a nut 8, which acts against the inside of the rim. .Interposed between the nut and rim I: propose to employ a washer 9, of some suitable material, but preferably of wood, with its grain running in the direction of the compression strain or substantially parallel to the tension members The object in cutting the washers so that the grain runs in this direction is to provide a wooden washer which will withstand the severecompression strain to which the washer is subjected. \Vith this construction any one portion of the rim is prevented from being thrown out of shape by the tightening of the tension member acting on some other portion of the rim and all parts of the rim may be placed under proper tension.

In the arrangement of tension members shown in Fig. a I prefer to provide that tension member which passes through the short section A of the rim with check or abutment nuts either side thereof, so that the tension of this portion of the rim may be maintained at the proper point.

In Figs. 7 and 8 I have illustrated still a different way of arranging the tension members (6 In Fig. 7 said tension members are all secured at one end to an anchor-piece 20, secured to the front rail 21 of the soundingboard, said tension members extending radially from the anchor-piece.

If desired, I may arrange the tension members 5 in different horizontal planes, as best seen in Fig. 9, part of said tension members being secured to the upper edge of the rim A and the others being secured to the lower edge of said rim. Any of the tension members desired or thought necessary may be socured to the upper edge of the rim and the others to the lower edge of the rim. I find good results are secured by arranging the alternate tension members at the upper edge of the rim. The remainingtension members, being in the lower horizontal plane, are secured to the lower edge of the rim. This up-anddown arrangement, of tension members may be employed on any one of the various forms of my invention shown in the drawings, whether said tension members extend clear across the piano-frame, as shown in Fig. 4t,

or extend to an anchor-piece, as shown in the other figures.

In Fig. 10 I have shown what might be termed a forked tension member'that is, a tension member having two branches which are arranged one above the other and which diverge and are secured at their ends to the upper and lower edge of the rim, respectively. In this construction the two branches (66 of said tension member are connected at their inner ends to a forked member ((7, which is secured to the anchor-piece 3 in any suitable way.

I prefer to arrange the posts 22 of the piano, as shown in Figs. 7 and 8, so that they diverge from the rim toward the front rail 21. lVith this construction they engage the rail 21 at two points separated from each other, and, as herein shown said posts come together at the point where they meet the rim A. In Fig. 7 I have shown my new form of post as applied to a piano having a symmetrical shape and in Fig. 8 said form of posts applied to an ordinary grand piano. In both forms 23 designates shoulders or projections against which the usual horns on the plate of the piano abut. 7

-From the above it will be seen that the invention is not limited to any particular shape or style of piano and maybe applied to any piano.

The particular arrangement of tension members herein illustrated is only my preferable arrangement, and other arrangements may be made without departing from the invention.

I desire to state that I. prefer to use the check-nuts 8 and 9, yet it is not always necessary to apply these to all the tension members.

Having described my invention, what I claim as new, and desire to secure by Letters Patent. is

1. In piano construction, a rim to support the sounding-board and tension members connected with said rim, said members each having a slightly-tapering head extending substantially through the rim and received in a correspondingly-shaped recess therein.

2. In piano construction, a rim to support a sounding-board, and tension members connected to said rim, said members having adjustable frusto-conical heads received in cor- 1espondingly-shaped recesses in the rim.

3. In piano construction, a rim to support a soundingboard,and adjustable tension members connected with said rim, each tension member having a tapering head received in a correspondingly-shaped recess in the rim, each head having a length substantially equal to the width of the rim.

4:. In piano construction, a rim to support a sounding-board, tension members connected with the rim, each member having a tapering head received in a correspondingly-shaped recess in the rim, and an abutment to engage the inside of the rim.

5. In piano construction, a rim to support a sounding-board, a plurality of tension members connected to the rim, each tension member having a tapering head received in a correspondingly-shaped aperture in the rim, combined with an abutment or stop adjustably mounted on each tension member and acting against the inside of the rim.

6. In piano construction, a rim to support a soundingrboard, tension members connected to said rim, anut on each tension member coacting with the inside of the rim, and a washer between the nut and said rim, said washer being shaped to fit the rim.

7. In piano construction, a rim to support a sounding-board, tension members connected to said rim, anut on each tension member coacting with theinside of the rim, and a wooden washer between the nut and said rim, said washer having its grain extending in a direction parallel to the thrust thereon.

8. In piano construction, a rim to support a sounding-board, tension members connected to said rim, and a nut adjustable on each tension member and coacting with the inside of the rim.

9. In piano construction, a rim to support the sounding-board, and adjustable tension members connected with said rim, a portion of said members being connected to the upper half of the rim, and the other members being connected to the lower half.

in testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

\Vitnesses:

Louis 0. SMITH, IVIA GARWI A. DUNN. 

